This invention pertains to absorption dynamometers, and in particular to a method of calibrating or checking the calibration of the torque measuring device.
Means of measuring torque generally fall into two categories: in-line (rotating) and reaction (stationary). Reaction torque measurements are used with air dynamometers, but they are inaccurate, being subject to errors introduced by aerodynamic effects associated with the exhaust of the engine being tested, the exhaust of the dynamometer, and local external air velocities. In-line torque measurements have also been used, but prior in-line torque meters have various drawbacks.
Most torque measuring systems require rotational movement of the measuring system to generate torque information. Because the measuring system must be rotating, it is difficult to calibrate or to check the calibration of the system once it has been installed. Frequently, calibration can only be performed under controlled conditions, such as in a testing laboratory.
The foregoing illustrates limitations known to exist in present dynamometer torque measuring devices and methods of checking the calibration of dynamometer torque measuring devices. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.